As Firefox 38.0.5 was just released, Firefox 39 reached beta stage and Firefox 40 entered the developer channel. Mozilla has Implemented the Google’s download protection from potentially unwanted software (Chrome already has it, check this blog post) in the Firefox developer edition.

Firefox browser with Unwanted Software Protection feature

Till now Firefox browser uses Google’s safe browsing feature to protect users from visiting malware and phishing sites, now it guards you against unwanted software too.

When you visit unwanted software page like this (don’t fear! It’s just a test page) warning will be shown (check the below screenshot)

Firefox reports unwated software page

READ: How to make Firefox browser safe against Logjam Attack

Reported Unwanted Software Page!

This web page at has been reported to contain unwanted software and has been blocked based on your security preferences.

Unwanted software pages try to install software that can be deceptive and affect your system in unexpected ways.

You can get out of that page or redirected to Mozilla’s phishing and malware protection documentation page when you click ‘Why was this page blocked?’

What’s new in Firefox 40 Developer Edition

Apart from unwanted Software protection, Mozilla has designed a new style for Add-ons manager based on the In-content Preferences style (check the screenshot below). This release introduces new performance tools. E10s or Project Electrolysis is enabled by default for testing.

Add-ons manager old and new style

SEE: How to Opt-out of /Remove Suggested Tile Ads from Firefox New Tab Page

Download Firefox 40 DE (offline install link)

Firefox 40 developer Edition release notes